Generating milling cutters belong to the so-called toothing tools which compete with grinding tools in the manufacturing of heavy duty transmissions such as for example for rolling machines, crans, diggers or textile machines. For the smoothing of hardened gears having straight or inclined toothings it has become known to use milling cutters having supporting teeth disposed along a helical line at the periphery of a supporting body and to mount thereon hard cutting blades which consist e.g. of carbides. As to the cutting blades initially blanks are formed which subsequently are soldered to the supporting teeth. Thereafter a grinding operation is performed on the milling cutter by a relatively complicated grinding method. Such milling cutters operate satisfactorily, however, do have some advantages.
The soldered hard metal tips are extremely temperature sensitive. The soldering operation may cause stresses and accordingly fissures and ruptures. As already mentioned, the cutting tips are ground while they are on the supporting body. Such machining may result in differently heated zones in the area of the cutting tips, which also may cause fissures and ruptures. If, in the making of a milling cutter, just one cutting edge will be damaged, there is no possibility to replace the latter; on the contrary the total milling cutter has to be considered to be scrap because renewed soldering will cause a deformation of the basic body.
The cutting edges have to be reground from time to time. To this end a special grinding machine is required which must be available at the user's if he does not wish to return the milling cutter to the manufacturer for grinding purposes.
The cutting edges of hard metal are very delicate. Accordingly, in the handling of the milling cutter it may readily occur that the cutting edges break when they are hit by other objects. Also in this case the total milling cutter cannot be used any longer.
For reasons of increased stability under load and high quality machining it is often desired to provide the cutting edges with a corresponding coating, for example of titanium nitride (TIN). Such a coating must be provided after the cutting tips have been mounted and ground. Accordingly, it is necessary to introduce the total supporting body into a coating oven which causes problems with respect to large volume milling cutters because most of the coating ovens are of too small receiving capacity. Furthermore, the coating operation is affected by soldering gases and the soldering connection will be of reduced strength.
The problem to be solved by the invention is to provide a generating milling cutter of the above-identified type, the making of which results in minimal scrap, which enables the use of cutting blades of hard metal or cermet and which allows for simple regrinding by the user.